It's no coincidence that California, land of the experimental health regimen, was home to Judy Mazel's wildly successful 1981 best seller, The Beverly Hills Diet. An aspiring actress with no medical training, Mazel became frustrated in her quest to lose weight and invented her own program, which required eating fruit for 10 days and consuming just one type of food, such as carbs or proteins, at a time. Panned by health professionals, Mazel struck a chord with dieters who believed that self-educated people often know better than experts. In the '80s, Mazel, who said she lost 72 lbs. (33 kg) on...